An oxygen isotope record fromthe Foscagno rock-glacier ice core,Upper Valtellina, Italian Central Alps
New high-resolution isotopic records (delta O-18, delta D and deuterium excess), from an ice core drilled in the Foscagno rock glacier ( Italian Central Alps), are presented. The delta O-18 data suggest a clear division between an upper part (2.5 and 4 m), showing relatively homogeneous values, and...
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Online Access: | http://hdl.handle.net/11383/1674314 https://doi.org/10.1177/0959683607082438 |
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ftuninsubriairis:oai:irinsubria.uninsubria.it:11383/1674314 2024-04-14T08:12:57+00:00 An oxygen isotope record fromthe Foscagno rock-glacier ice core,Upper Valtellina, Italian Central Alps STENNI B GENONI L GUGLIELMIN, MAURO Stenni, B Genoni, L Guglielmin, Mauro 2007 http://hdl.handle.net/11383/1674314 https://doi.org/10.1177/0959683607082438 eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:000251541400016 volume:17 (7) firstpage:1033 lastpage:1039 numberofpages:7 journal:THE HOLOCENE http://hdl.handle.net/11383/1674314 doi:10.1177/0959683607082438 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-36348965884 info:eu-repo/semantics/closedAccess rock glacier delta O-18 delta D isotope relict glacier ice permafrost Holocene Italian Alps info:eu-repo/semantics/article 2007 ftuninsubriairis https://doi.org/10.1177/0959683607082438 2024-03-21T18:53:31Z New high-resolution isotopic records (delta O-18, delta D and deuterium excess), from an ice core drilled in the Foscagno rock glacier ( Italian Central Alps), are presented. The delta O-18 data suggest a clear division between an upper part (2.5 and 4 m), showing relatively homogeneous values, and a middle part (4 - 7.65 m), showing seasonal variations of this parameter. The isotopic analyses confirm previous results (crystallographic and chemical analyses) suggesting a division of this relict glacier ice body into an upper part, between 2.5 and 4 m, where melting and refreezing processes occur, and a middle part, between 4 and 7.65 m, where the isotopic signal is preserved. Larger deuterium excess variations (d = delta D - delta*delta O-18) are found in the massive ice (below 4 m depth) rather than in the overlying ice. These are in antiphase with the delta O-18 but without any clear correspondence with the presence of the debris layers. Postdepositional processes could have affected, at least partially, the isotopic content of the original precipitation. The radiocarbon dating of a leaf (Salix spp.) found in the massive ice from another nearby borehole in the same rock glacier gave a calendar age ranging between AD 765 and 1260. The expected delta O-18 values of the present-day precipitation in the Foscagno valley are of the same order as those found in the massive ice (-12.4%). This similarity would suggest climate conditions not very different from present day, in good agreement with other available palaeoclimate reconstructions for this period. However, only more abundant precipitation would make the existence of a glacier possible in a climate not very different from that of the present. Article in Journal/Newspaper Ice ice core permafrost IRInSubria - Institutional Repository Insubria (Università degli Studi dell’Insubria) The Holocene 17 7 1033 1039 |
institution |
Open Polar |
collection |
IRInSubria - Institutional Repository Insubria (Università degli Studi dell’Insubria) |
op_collection_id |
ftuninsubriairis |
language |
English |
topic |
rock glacier delta O-18 delta D isotope relict glacier ice permafrost Holocene Italian Alps |
spellingShingle |
rock glacier delta O-18 delta D isotope relict glacier ice permafrost Holocene Italian Alps STENNI B GENONI L GUGLIELMIN, MAURO An oxygen isotope record fromthe Foscagno rock-glacier ice core,Upper Valtellina, Italian Central Alps |
topic_facet |
rock glacier delta O-18 delta D isotope relict glacier ice permafrost Holocene Italian Alps |
description |
New high-resolution isotopic records (delta O-18, delta D and deuterium excess), from an ice core drilled in the Foscagno rock glacier ( Italian Central Alps), are presented. The delta O-18 data suggest a clear division between an upper part (2.5 and 4 m), showing relatively homogeneous values, and a middle part (4 - 7.65 m), showing seasonal variations of this parameter. The isotopic analyses confirm previous results (crystallographic and chemical analyses) suggesting a division of this relict glacier ice body into an upper part, between 2.5 and 4 m, where melting and refreezing processes occur, and a middle part, between 4 and 7.65 m, where the isotopic signal is preserved. Larger deuterium excess variations (d = delta D - delta*delta O-18) are found in the massive ice (below 4 m depth) rather than in the overlying ice. These are in antiphase with the delta O-18 but without any clear correspondence with the presence of the debris layers. Postdepositional processes could have affected, at least partially, the isotopic content of the original precipitation. The radiocarbon dating of a leaf (Salix spp.) found in the massive ice from another nearby borehole in the same rock glacier gave a calendar age ranging between AD 765 and 1260. The expected delta O-18 values of the present-day precipitation in the Foscagno valley are of the same order as those found in the massive ice (-12.4%). This similarity would suggest climate conditions not very different from present day, in good agreement with other available palaeoclimate reconstructions for this period. However, only more abundant precipitation would make the existence of a glacier possible in a climate not very different from that of the present. |
author2 |
Stenni, B Genoni, L Guglielmin, Mauro |
format |
Article in Journal/Newspaper |
author |
STENNI B GENONI L GUGLIELMIN, MAURO |
author_facet |
STENNI B GENONI L GUGLIELMIN, MAURO |
author_sort |
STENNI B |
title |
An oxygen isotope record fromthe Foscagno rock-glacier ice core,Upper Valtellina, Italian Central Alps |
title_short |
An oxygen isotope record fromthe Foscagno rock-glacier ice core,Upper Valtellina, Italian Central Alps |
title_full |
An oxygen isotope record fromthe Foscagno rock-glacier ice core,Upper Valtellina, Italian Central Alps |
title_fullStr |
An oxygen isotope record fromthe Foscagno rock-glacier ice core,Upper Valtellina, Italian Central Alps |
title_full_unstemmed |
An oxygen isotope record fromthe Foscagno rock-glacier ice core,Upper Valtellina, Italian Central Alps |
title_sort |
oxygen isotope record fromthe foscagno rock-glacier ice core,upper valtellina, italian central alps |
publishDate |
2007 |
url |
http://hdl.handle.net/11383/1674314 https://doi.org/10.1177/0959683607082438 |
genre |
Ice ice core permafrost |
genre_facet |
Ice ice core permafrost |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000251541400016 volume:17 (7) firstpage:1033 lastpage:1039 numberofpages:7 journal:THE HOLOCENE http://hdl.handle.net/11383/1674314 doi:10.1177/0959683607082438 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-36348965884 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1177/0959683607082438 |
container_title |
The Holocene |
container_volume |
17 |
container_issue |
7 |
container_start_page |
1033 |
op_container_end_page |
1039 |
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1796310802626510848 |